A product information processing apparatus (e.g., POS terminal) normally includes a printer for issuing receipts. The printer mounted on the product information processing apparatus generally prints information on transaction details and the like on paper taken out from a roll of paper. Therefore, many printers include a holder for storing the roll of paper.
A diameter of the roll of paper gradually becomes small with use. In some cases, the printer includes a drop portion at a bottom portion of the holder for notifying a user that a time to exchange the roll of paper has come. The drop portion is a portion where the roll of paper falls and fits into when the diameter of the roll of paper becomes small. A sensor for detecting the roll of paper is provided in the drop portion. As the sensor detects the roll of paper, the printer notifies the user that the time to exchange the roll of paper has come.
For reducing a loss of a remaining amount of the roll of paper, it is desirable to make a width of the drop portion in a diameter direction as small as possible so that the roll of paper is not fit into the drop portion while there is still a large amount of paper left. Further, it is desirable to set the drop portion deep so that the roll of paper is not erroneously detected by the sensor. In this case, however, since the roll of paper is deeply and stably fit into the drop portion, it becomes difficult for the user to take out the roll of paper from the drop portion when replacing the roll of paper.